Electric resistor support



?atented Dec. 1, 1925.

UNITED STATES T-RIC 8a MANFACTURNG COIYIBANY,

A COEPORATGN OF RENNSYLVANIA.

- ELECTRIC EESSTO?, S'UPORT.

Application filed Apr1-21, `11324.

Be it known that i Emmer E. Surina- LAXD, a citizen of the United States. and a resident of Mansfield, in the county or Richland and State of Ohio, have invented a new and useful improvement in Electric Resistor Supports, of which the following is a specification.

iiv invention relates to electric heating units and particularly to supports for helical resistor members.

The object of my invention is to provide a simple and practical electric heating unit that is easily assembled and is rugged in construction.

,in practicing my invention, l provide a refractory plate of ele( i 'ic-ally insulating material. plurality of spiral grooves are provided in the upper surface of the plate, each having side walls that are angular-ly Adisposed to each other. Bridging members integral with the walls iof the grooves ei;- tend laterally therebetween and are provided to maintain in operative position, helically wound resistor members that are threaded into the grooves and extend longitudinally thereof.

In the Single sheet of drawings,

Figure 1 is a top plan view'of an electric f heating unit employing my invention; and

Fig. 2 is a sectional view of the electric heating unit shown in Figure 1, taken along the line H H of Figure 1.

ifi refractory electrical insulating member 11 supports terminals 12, 13, and 14tin a manner hereinafter more fully described. A pair of spiral grooves 15 and 1G are pro-r vided in the refractory member 11 and are so constructed that in a cross section taken at right angles to a tangent thereof, the walls 17 and 18 o f one groove, and 19 and 21 of the other groove are disposed angularly relatively to each other. Bridging members 22, that are integral with the plate 11, extend between the walls 17, 18, 19 and 21 laterally thereto and are disposed at suitable intervals along the grooves.

Resistor members 23 and 25: are located in the grooves 15 and 16, respectively, and are maintained in operative position therein by the bridging members 22. Bolts 25, 26 and 2T are provided to secure resistor members 23 and 2li at their ends thereof to the refractory member, and are connected by Serial No. 707,814.

conductors 28, 29 and 31 to terminal members 12, 13 and 1d. rllhe refractory memberv 11 is perforated and countersunk at S32, 33 and 234 to provide a practical means for locating bolts 25, '26,and in operative position. The refractory member 11 isalso perforated at 85, 36 and 237 to provide practical means foi' securing ythe 'hea-ting unit to any supporting means not shown.

rierminal members 12, 13 and 111 are supported by a refractory member 38 of partially rectangular and partially arcuate shape that is .secured to the refractory member 11 by bolts .89 and 11 extending therethrough. L

In assembling the heating unit resistor the members and 2aare threaded through the grooves 15 and 16 and are secured to the refractory member 11 at their ends by the bolts 25, 2G and 27. The conductors 28, 2) and 31 are threaded through the terminal supporting member lland are connected to the resistor members 213 and'241 and maintained in operative relations therewith by the bolts `25, 26 and 27. T he terminal supporting member 38 `is secured-to the refractory member 11by the boltsr39and 41.

The diameter of `the helix vis made relatively large so ithat it will .bezilocated well above the bottom of the groove of V- shape. rfhe helically wound resistor member therefore operatively engages the side walls with a line contact only. The flow of heat by direct conduction from the wire to the refractory support is, therefore, reduced to a very small amount, and this results in transmitting a larger percentage of the heat generated in the wire by direct radiation to material placed on or above the grooved supporting member 11. lThis results also, in a quicker heating up of the unit. The hot spot, which usually is present immediately beneath the bottom portion of the wire helix when located in a groove having a rounded bottom, is entirely avoided.

This construction therefore permits of obtaining a quick initial heating, a reduced flow of heat downwardly and the avoidance of dangerous hot spots and, in general, the operation of this heating unit is very similar to the operation of an open type of heating unit.

it is obvious that a structure embodying my invention provides a simple, practical electric heating unit that is easily assembled and that may be readily disassembled to permit a renewal of resistor members.

Various modifications and changes may be made without departing from the spirit and scope of the invention, and I desire therefore that only such limitations shall be placed thereon as are imposed by the prior art or are set forth in the appended claims.

I claim as my invention:

l. An electric heating unit con'iprising a helically wound resistor member, and a re fractory electrically insulating member having grooves for supporting said resistor member, the walls of said grooves being so constructed as to maintain a line contact only with said resistor member.

2. In an electric heating unit, the combination with a refractory electrically insulating member having a grooved portion, of a helically wound resistor member supported by the walls only of said grooved portion.

3. In an electric heating unit, the combination with a refractory electrically insulating member having a grooved portion whose section has non-parallel sides, of a helically wound resistor member, supported in said grooved portion by the walls thereof.

4:. In an electric heating unit, the combination with a refractory electrically insulating member having a grooved portion, said grooved portion having longitudinally `spaced bridging members'extending laterally between the walls of said grooved portion, of a helically wound resistor member supported by the walls only of said grooved portion, and maintained in operative posi tion by said bridging members.

5. In an electric heating unit, the combination with a refractory electrically insulating member having a grooved portion, said grooved portion having longitudinally spaced bridging members extending laterally between the Walls of said grooved portion and having a cross section of nonparallel sides, of a helically wound resistor member supported in said grooved portion by the walls thereof and maintained in operative position by said bridging members.

6. In an electric heating unit, the combination with a refractory electrically insulating member having a grooved portion, of a helically wound resistor member sup ported by the walls of said grooved portion and maintained in line contact only therewith.

7. In an electric heating unit, the combination with a refractory electrically insulating member having a grooved portion, said grooved portion having longitudinally spaced bridging members extending laterally between the walls of said grooved portion and having a cross section of non-parallel sides, of a helically wound resistor member so supported in said grooved portions by the walls thereof as to maintain a line contact only with said walls, and maintained in operative position by said bridging members.

In testimony whereof, I have hereunto subscribed my name this tenth day of April 1924.

ERNEST E. sU'rHnRLiiNn. 

